Hey guys. I was giving my car a once over today and noticed there's no vacume hose on this vacume tree.. Its the one right next to the distributor on my l98 iroc. There's 2 other ports that have vacume lines but this bigger one doesn't. It's also cleaner then the rest of the engine which leads me to believe it had a vac hose on it.. Can someone tell me if a hose belongs on this bac tree or what it's for? I've read possibly egr related but I'm not sure. Thanks as always guys.

 

That's the egr solenoid. The port with no line is a vent. When the solenoid releases the vacuum from the egr valve it vents with that port.

 

Ah, thank you sir